Candidate: This is a K08 application for Shulamite Green, Ph.D., an F32 postdoctoral fellow at the University of California Los Angeles (transitioning to assistant professor by the award start date). Dr. Green's career goal is to become an independent investigator and leader in the field of sensory over-responsivity (SOR) from an interdisciplinary and transdiagnostic perspective. This K08 award will provide Dr. Green with the necessary training to gain expertise in 1) behavioral and psychophysiological methods of assessing SOR; 2) advanced brain connectivity methods; and 3) the effect of early life stress on the development of brain, behavior, and risk for psychiatric disorders. Environment: Mentorship will be provided by Drs. Susan Bookheimer, Michelle Craske, and Nim Tottenham, experts in cutting-edge neuroimaging methods, psychophysiology and translational research, and the effect of early life stress on the brain, respectively. Research and Career Development: Sensory over-responsivity (SOR) is an impairing condition manifested as extreme sensitivity to stimuli such as being touched, scratchy clothing, or loud noises. SOR is pervasive across neurodevelopmental disorders with both genetic and environmental causes, including over 50% of children with autism spectrum disorders (ASD) and those with early life stress. However, little is known about the underlying mechanisms for risk and resilience to SOR across populations, and SOR is not well identified or treated in most clinical groups. The proposed study will integrate behavioral, psychophysiological, and neuroimaging methods to characterize SOR across youth with ASD and those with early life stress. Participants will be 28 children with early life stress due to adoption from foster care (AFC), 28 with ASD and 28 age- and IQ-matched typically developing (TD) controls, ages 8-16 years. The aims of the study include: 1) examining shared and distinct behavioral and pyschophysiological markers of SOR as well as their relation to mental health difficulties and social competence; 2) using functional imaging (fMRI) to test whether SOR is related to similar patterns of neural responsiveness, habituation, and functional connectivity during sensory stimulation in AFC, ASD, and TD youth; and 3) examining group differences in the effect of distracting auditory stimuli on reaction time, physiological arousal, and functional brain connectivity during emotion identification. This work will contribute to the field by facilitating an interdisciplinary understanding of SOR as a transdiagnostic phenotype with implications for improvement of targeted assessment and intervention. These aims are consistent with the Research Domain Criteria (RDoC) framework as well as the NIMH strategic plan to focus on individual differences in brain circuitry across diverse populations as a source of risk and resilience for mental illness. This research will lay the foundation for Dr. Green's career as a leading expert in the neurobiology of SOR. Results will support a future R01 grant focused on common and distinct neural pathways of SOR across populations, as well as the refinement of SOR identification and treatment tools to target specific populations.